Papersheet is written in SASS. I created a css-overwrite to personalize it. To do that, just load one of the two scss-files and change the variables how you like them. Then you need to compile this SASS. Do this either on your computer or in an online-tool like SASS Meister. It is important to note, that you need to link the Webfont you want to use in your head, or make sure you use a font Blogger has included.